Photographic coloring element and process

ABSTRACT

A film for producing a color image from a monochromatic image comprising at least a first layer of emulsion having a color coupler for producing a negative or a positive image in a first color of the monochromatic image. A second layer of emulsion has a second type of color coupler for producing an image in a second color with luminances reversed with respect to the image formed in the first layer. The two additional layers of emulsion each contain the same type of color coupler so that the two additional layers produce a positive masked negative image or a negative masked positive image of the monochromatic image in a third color whereby the developed film produces a colored image of the monochromatic image. A novel process for producing the colored image from the monochromatic image is also disclosed.

United States Patent [191 Silverman [451 Mar. 19, 1974 PHOTOGRAPHICCOLORING ELEMENT AND PROCESS Avrum Silverman, 2809 Avenue K, Brooklyn,NY. 11210 [22] Filed: Aug. 11, 1971 [21] Appl. No.: 170,880

[76] Inventor:

Primary Examiner-Norman G. Torchin Assistant Examiner-Alfonso T. SuroPico Attorney, Agent, or Firm-Ryder, McAulay, Fields, Fisher & Goldstein[5 7] ABSTRACT A film for producing a color image from a monochromaticimage comprising at least a first layer of emulsion having a colorcoupler for producing a negative or a positive image in a first color ofthe monochromatic image. A second layer of emulsion has a second type ofcolor coupler for producing an image in a second color with luminancesreversed with respect to the image formed in the first layer. The twoadditional layers of emulsion each contain the same type of colorcoupler so that the two additional layers produce a positive maskednegative image or a negative masked positive image of the monochromaticimage in a third color whereby the developed film produces a coloredimage of the monochromatic image.

A novel process for producing the colored image from the monochromaticimage is also disclosed.

20 Claims, 2 Drawing Figures III PATENIEWMQW 3.798037 FIG. i.

FIG. 2.

INVENTOR AVRUM SILVER MAN ATTORNEY.

PHOTOGRAPHIC COLORING ELEMENT AND PROCESS This invention relatesgenerally to a photographic coloring element and a process thereforeand, more particularly, pertains to an element for rendering a coloredimage from a monochromatic or a black and white image and a novelprocess for accomplishing the same.

Present techniques for generating a colored image from a colorless orblack and white source image usually require the use of expensive andcomplex equipment, as well as the utilization of processes which must beperformed by a skilled technician in laboratory surv roundings undercontrolled conditions. Thus, in the photographic field color separationtransparency records and various combinations of exposures from lightsources of different frequencies for both taking and viewing the pictureare necessary to produce a multicolored image from a black and white ormonochromatic source image. As a result, such pictures are extremelycostly to produce.

Accordingly, an object of this invention is to provide an improvedphotographic color process.

A more specific object of the present invention is to provide aphotosensitive element which produces a colored image from amonochromatic source image which is simple to produce.

A further object of the present invention is the provision of a film forproducing colored images from a black and white source which may beutilized for medical purposes to produce a colored image of portions ofthe body to facilitate the interpretation of X-rays, for example.

Another object of this invention resides in the novel details ofconstruction which provides a photosensitive element of the typedescribed which produces a realistic and attractive colored image from acolorless source image.

Accordingly, a photosensitive element for producing a colored image froma monochromatic image constructed according to the present inventioncomprises a film having at least a first layer means for producing apositive image of said monochromatic image in a first color. Second andthird layer means is provided for producing a negative masked positiveimage of the monochromatic image in a second color. Additionally, fourthlayer means is provided for producing a negative of the monochromaticimage in a third color, whereby the developed film produces a realisticcolored picture of the monochromatic image.

A feature of the present invention is to provide a method for producinga colored image from a colorless or monochromatic source image in asimple and easy manner.

Other features and advantages of the present invention will become moreapparent from a consideration of the following detailed description whentaken in conjunction with the accompanying drawing, in which:

H6. 1 is a sectional view, to an enlarged scale, of a photosensitiveelement constructed in accordance with the present invention; and

FIG. 2 is a sectional view, to an enlarged scale, of a modifiedembodiment of a photosensitive element of the type shown in FIG. 1.

Before discussing the element and method of the present invention, it isbelieved that a brief review of the principles of reversal color filmwill facilitate an understanding and appreciation of the presentinvention. Accordingly, where a picture of a colored scene is taken withconventional color reversal film and the color red is present in theoriginal scene, after processing the color red is transmitted throughthe film but the colors blue and green are absorbed. When the color blueis present in the original scene, after processing the blue color istransmitted through the film but the red and green colors are absorbed.Similar comments apply where the color green is present in the originalscene. That is, the green color is transmitted through the film but thered and green colors are absorbed.

In e ffec tfthis a ction may be th'au sraras'siazfian three naturalopposites. To be more specific, the action may be thought of as havingthe red color opposite the blue and green colors; the blue coloropposite the red and green colors; and the green color opposite the redand blue colors, as in a natural color triangle wherein each color ispositioned at a different apex.

The present invention, however, is not directed to a colored scene but ablack and white or monochromatic scene which may be present in either anegative or a positive. Thus, two apexes of the color triangle red,green, and blue may be derived from the respective negative and thepositive of the black and white or monochromatic image. That is, theblack and white image, which may be a negative for example, permits theproduction of a positive which is the opposite of the negative image ingray scale, (i.e., the luminances are reversed). On the other hand, ifone begins with a black and white positive image, a negative image maybe derived therefrom which is the opposite or reversed in gray scale ofthe positive image. As a result, as noted above, the negative andpositive images being opposite in gray scale may be used as two apexesof an artificial color triangle.

in accordance with the present invention, the third apex of theartificial color triangle is produced by a positive masked negativeimage or a negative masked positive image. These masking images areproduced in such a manner as to provide a substantially third oppositein gray scale to the gray scale of a normal positive and the gray scaleof a normal negative.

The primary colors red, green, and blue are then assigned to the threeopposite images so produced. For example, the positive image may beproduced in a minus-red layer of emulsion, the negative image may beproduced in the minus-blue layer of emulsion, and the negative maskedpositive, may be produced in two minus-green layers of emulsion. It isto be noted that this assignment of color values is for illustrativepurposes only and is not to be interpreted as being a limitation of thepresent invention. That is, the invention contemplates any combinationof the assignment of color values. Thus, the positive may be produced inthe minus-blue layer and the negative may be produced in the minus-redlayer, for example.)

A consideration of the above illustrates that, in effect, a coloropposition arrangement has been produced which is analogous to the coloropposition arrangement produced by conventional reversal color film.That is, the positive image (which is transmitted by the minus-red layerin the example under consideration) will have luminances opposite to thenegative image (which is transmitted by the minus-blue layer) and thecomposite masked image (which is transmitted by the two minus-greenlayers).

If the colored images are superposed one on the other it will be obviousthat a complete range of colors can be produced from the monochromatictones of the original black and white image. While it is also obviousthat the colors so produced will not correspond exactly to the colors inthe original scene, it has been found that they are neverthelessrealistic and attractive and are translated in a logical progression.

It is to be noted that conventional black and white photography dealswith the rendering of colors in an original scene into monochromeaccording to their visual luminosities. The present invention deals withthe converse; the rendering of monochromatic tones in colors accordingto their visual luminosities. That is, the invention relates to asubtractive color film and process for translating varying shades ofgray recorded on black and white film into hues of color on the new filmwherein each hue of color corresponds to a respective shade of gray,white, or black.

More specifically, FIG. 1 illustrates a photosensitive element whichwill render a black and white or monochromatic image as a colored imageupon development. Although in the discussion which follows it will beassumed that the element of FlG. 1 is a film to be used with a black andwhite negative to produce a color transparency, it is to be understoodthat instead of a film the same construction may be utilized as printingpaper, in which case the support may be changed so that it is a whitereflecting paper base, as noted in greater detail below. Moreover, it isobvious that, the element may be used with a black and white positive,in which case the types of images produced in the emulsion layers asnoted below will be reversed (i.e., a negative image will be produced ina layer which produces a positive image when the film is used inconjunction with a black and white positive).

The photosensitive element of FIG. 1 is designated generally by thereference numeral and includes a support 12. The support 12 may be aconventional safety film made of cellulose acetate, or cellulosebutyrate, or polyester. If the element 10 is to be used as a printingpaper the support 12 may be a white reflecting paper base.Alternatively, the support 12 may be a white-pigmented plastic sheetmade of opaque cellulose acetate.

Mounted on the support 12 is a layer 14 of colloidal silver which servesas a conventional antihalation backing and is bleached away duringprocessing. Deposited or superposed on the layer 14 is a first emulsionlayer 16 which is a thick coating of extremely low contrast panchromaticemulsion and contains color couplers. The layer 16 yields, upondevelopment, an extremely low contrast positive dye image which may becyan in the example under consideration.

Deposited or superposed on the layer 16 is a plan gelatine interlayerl8. Deposited or superposed on the layer 18 is a second emulsion layer20 which is a thick coating of extremely high contrast panchromaticemulsion and contains color couplers. The layer 20 yields upondevelopment, an extremely high contrast positive dye image, which may bemagenta in the example under consideration.

Deposited on the layer 20 is a layer of colloidal silver 22 which servesas a conventional yellow filter and is bleached away during processing.Deposited or superposed on the layer 22 is a third emulsion layer 24which is a thin coating of extremely high contrast panchromatic emulsionand contains color couplers. The layer 24 yields, upon development, anextremely high contrast negative dye image, which may be magenta in theexample under consideration.

Deposited or superposed on the layer 24 is a plain gelatine interlayer26. Deposited or superposed on the layer 26 is a fourth emulsion layer28 which is a thin coating of extremely low contrast panchromaticemulsion and contains color couplers. The layer 28 yields, upondevelopment, an extremely low contrast negative dye image, which may beyellow in the example under consideration.

The layers 20 and 24 produce a magenta image in the example underconsideration. However, the image produced in the layer 20 is a positiveimage while the image produced in the layer 24 is a negative image.Thus, the layers 20 and 24 may be thought of as collectively forming acomposite layer which produces what may be termed a negative maskedpositive image. A]- ternatively, if the film 10 were used with apositive the layers 20 and 24 would produce a positive masked negativeimage.

The emulsions used with the present invention may be sensitive to theentire visible spectrum of light. They contain a light sensitive silverhalide, plus a coupler which is capable of reacting with oxidizeddeveloper to produce a dye of the appropriate color. The developer usedis capable of the coupling action which produces dye images, as well asreducing the exposed silver halide grains to metallic silver.

The bottom two emulsion layers 16 and 20 should be thicker than the toptwo emulsion layers 24 and 28, because comparable image areas must bedeveloped twice in the bottom two emulsion layers while only once in thetop two emulsion layers. The structure of the element 10 is such as toyield upon reversal development two positive dye images in therespective layers 16 and 20, and two negative dye images in therespective layers 24 and 28, inseparably superposed on the same support12.

The element 10 is exposed and processed according to the followingprocedure:

A black and white negative (or positive, as noted above) is printed bycontact or enlargement onto the element 10. This first exposure is madewith white light which penetrates and records in the four emulsionlayers 16, 20, 24, and 28. The antihalation backing l4 prevents theblurring of the image. The element is then passed through a firstdeveloper to reduce the exposed silver halide grains in all fouremulsions to metallic silver. The thinner top emulsions, layers 24 and28, receive full development during the development time interval butthe thicker bottom emulsions, layers 16 and 20, are only partiallydeveloped during this interval. The reduction of layers 16 and 20 iscompleted later. However, it is to be understood that enough silverhalide and color couplers remain in these image areas in the bottomemulsion layers 16 and 20, to react with the color developer later inthe processing. The element 10 then is passed through a stop bath whichneutralizes the developer and halts its action.

The element is thereafter evenly fogged in blue light which affects onlythe top emulsion layers 24 and 28. The yellow filter 22 prevents theblue light from reaching the bottom emulsions, layers 16 and 20. Theelement is then passed through a color developer which reduces the newlyexposed silver halide grains in the top emulsion layers 24 and 28, andcompletes the rehigh contrast material with too short an exposure rangefor the average black and white negative. Taking the example of anegative with an opacity range of 31 to l to be printed on a color paperof the present invention;

sure range for the average black and white negative, and emulsion layers20 and 24 are manufactured of duction of the remaining silver halidegrains in the bot- 5 emulsion layers 16 and 28 should have an exposuretom emulsion layers 16 and 20. At the same time, the range of 40 to 1,too long a range for the negative redeveloper forms suitable dyes byreaction with the cou sulting in a low contrast image while emulsionlayers 20 plers incorporated in all four emulsion layers. The eleand 24should have an exposure range of 24 to 1, too ment is thereafter passedthrough a stop bath which short a range for the negative resulting in ahigh conneutralizes the developer and halts its action. The elel0 ltrastimage. ment is then subjected to a bleaching solution which Thus asindicated in FIG. 1, emulsion layers 16 and converts all of the silverin the element to silver broi28 are man factured of low contrast mterial wi h a mide. This includes the yellow filter 22 and theantihadisposition toward underexposure and underdevellation backing 14which are both made of colloidal silopment while emulsion layers 20 and24 are manufacver. A con entional fixing solution (hypo) removes alltured of high contrast material with a disposition of the silver bromideleaving only the dye images in laytoward overexposure andoverdevelopment. y P

V W ers 16, 20, 24, and 28. cessing positive layer 16 (in the exampleunder consid- Thus, when the processing is completed the top eration) toan extreme low contrast and positive layer emulsion layers 24 and 28,which received the second 0 t0 an x r m ly g C nt ast, and ga layer 24exposure with blue light, will be reversed to negative to an extrem yhigh Contrast and negative layer 28 to dye images while the bottomemulsion laye 16 d an extremely low contrast, their respective grayscales -20, which received only the initial exposure will have andequivalent dye densities are deformed in a systemyielded positive dyeimages. atic way. The purpose of this deformation of the gray(Formulations for developing olution blea hi scales and equivalent dyedensities is directed toward solutions, and stop baths may be found inthe text entiproducing the weighted values, and, therefore, the retledDeveloping; The Negative Technique, copyright sulting color translationshown in Table I below.

ii TABLEI 7' m N i 8 if A B c D E F o H Gray Gray High High Negative LowLow Scale Scale Contrast Contrast Masked Cont. Cont. Res, Normal NormalPositive Negative Positive Pos. Neg. Color Positive Negative MagentaMagenta Magenta Cyan Yello Trans.

(Green) (Red) (Blue) White 8/8 Black 0 8/ 0 0 0 Re 7/8 1/8 8/8 2/8 2/85/8 0 Oran. 6/8 2/8 /8 4/8 0 Yel. 5/8 3/8 8/8 6/8 6/8 3/8 1/8 Yel.Gr.4/8 4/8 8/8 8/8 8/8 2/8 2/8 Green 3/8 5/8 6/8 8/8 6/8 1/8 3/8 BLGr. 2 86/8 3 s s 4/8 0 4/8 Cyan 1/8 7/8 2/8 8/8 2/8 0 5/8 GLBl. Black 0 White8/8 0 8/8 0 0 6/8 Blue 1966 by FocalTresslLiniited,iiiifitdEfiEzifFiifiF """xaarala'gr j col'u'nfn Xmustraesa ra scale for a by Charles Birchall and Sons Ltd, London, 16thEdinormal positive and column B illustrates a gray scale tion, edited byC. l. Jacobson.) for normal negative. Columns C, D, F, and G corre- Therelative contrasts of the respective negatives and spond to the dyeimages formed in the respective layers positives in the respective imagelayers specified above aft r de elopment. Thus, Column C corresponds tothe are critical and may be established by the following magefltaimageformed in layer 2 il C hmin DCOrmethod. Layers 16 and 28 are fabricatedof a slow responds to the magenta image formed in adjacent speedemulsion designed to b under/exposed i h layer 24. The theoreticaleffect or summation of layers time allowed for exposure, and layers 20and 24 are 20 and 24 is summarized in column E which illustratesfabricated of a fast speed emulsion designed to be overthe negativemasked positive- Column F corresponds to exposed in the time allowed forexposure. Additionally, the y image formed in layer 16 While Column Glayers 16 and 28 are fabricated of an emulsion constiresponds to theYellow image formed in layer tuted to develop slowly thus beingunderdeveloped i umn H is the resulting color translation of aparticular the time allowed for development, and layers 20 and 24 Shadeof gray, White, blackare fabricated of an emulsion constituted todevelop W515i in the high contrast positive( columnC) the quickly thusbeing overdeveloped in the time allowed highlights are blank and manytones toward the end of for development. Underexposure and underdevelthescale are also blank lacking density. Other tones opment will result ina low contrast image of the type contrast with each other. The highcontrast negative required while over-exposure and overdevelopment(column D) has the luminances reversed. Ideally, in the will result in ahigh contrast image of the type required low contrast positive (columnF) the brightest high- Additionally, emulsion layers 16 and 28 aremanufaclights will be denser than normal with the shadows betured of lowcontrast material with too long an expocoming opaque with density. Othertones are flat with little contrast. The low contrast negative (columnG) has the luminances reversed. The high contrast positive (column C)and high contrast negative (column D) mask each other, and create whatis in effect a completely new scale of transmittance (column B). Readingacross columns C, D, and E line by line reveals that genta, and cyan tothis system of color translation allows of various combinations ofpositive, negative, and negative masked positive. The three most usefulcombinations are detailed in Tables 1, 11, and 111. Table ll is obtainedby adding the weighted values of columns E, F, and G.)

Assigning the subtractive primaries of yellow, ma-

the lower weighted value in columns C and D always below is similar toTable l but illustrates the results ob-. acts as a light valve" for thehigher weighted value in tained when column C corresponds to the cyanimage columns C and D, thereby creating a new value in 001- formed inlayer 20, column D corresponds to the cyan umn E. (It should be notedthat these weighted values image formed in layer 24, column Fcorresponds to the are ideal and only approximate.) yellow image formedin layer 16, and column G corre- Therefore, reading across line 1 showsthat column sponds to the magenta image formed in layer 28. ln a E,which summarizes the theoretical effect of columns similar manner, Table111 below illustrates the results C and D, will transmit no discerniblegreen light. On obtained when column C corresponds to the yellow theother hand, the image represented by column F will image formed in layer20, column D corresponds to the transmit red light. However, sincecolumn F is a low yellow image formed in layer 24, column Fcorrespondscontrast scale, the red light will be of less intensity than t0 the mgenta image formed in layer 16, and column if column F were of a highcontrast. Column G reveals G wrr ponds t0 the cyan image formed in layer28,

r 7 7 m MW TABLE II A B C D E F G H Gray Gray High High Negative Low LowScale Scale Contrast Contrast Masked Cont. Cont. Res. Normal NormalPositive Negative Positive Pos. Neg. Color Positive Negative Cyan CyanCyan Yellow Magenta Trans.

(Red) (Blue) (Green) White 8/8 Black 0 8/8 0 0 6/8 0 Blue 7/8 1/8 8/82/8 2/8 5 8 0 Red Bl. 6/8 2/8 8/8 4/8 4/8 4/8 0 Magenta 5/8 3/8 8/8 6/86/8 3/8 1/8 Bl.Red 4/8 4/8 8/8 8/8 8/8 2/8 2/8 Red 3/8 5/8 6/8 8/8 6/81/8 3/8 Orange 2/8 6/8 4/8 8/8 4/8 0 4/8 Yellow 1/8 7/8 2/8 8/8 2 8 05/8 YeLGl-v Black 0 White 8/8 0 8/8 0 0 6/8 Green 'TABLFIII A a C D E FG H Gray Gray High High Negative Low Low Scale Scale Contrast ContrastMasked Cont. Contv Res. Normal Normal Positive Negative Positive Pos.Neg. Color Positive Negative Yellow Yellow Yellow Magenta Cyan Trans.

(Blue) (Green) (Red) White 8/8 Black 0 8/8 0 0 6/8 0 Green 7/8 1/8 8/82/8 2/8 5/8 0 BLGr. 6/8 2/8 8/8 4/8 4/8 4/8 0 Cyan 5/8 3/8 8/8 6/8 6/83/8 1/8 Gr.8l. 4/8 4/8 8/8 8/8 8/8 2/8 2/8 Blue 3/8 5/8 6/8 8/8 6/8 1/83/8 RedBl 2/8 6/8 4/8 3/8 4/8 0 4/8 Mag. l/8 7/8 2/8 8/8 2/8 0 5/8Bl.Red Black 0 White 8/8 0 8/8 0 0 6/8 Red 'Fliififiis'e'eiiiiisle'b'iiie'llgfitttillilse'8555617555 be If it is desired to print from apositive, as with motion image represented thereby. Thus for line 1where only pictures for example, the exposures are made in the red lightis transmitted, the resulting translation will be same manner as, inprinting from a negative. However, red. after processing, the topemulsion layers 24 and 28 will Similarly, the bottom line of the tableshows that the have been reversed to positive dye images while the imagerepresented by column F. Will transmit n0 bottom emulsions, layers 16and 20, will have yielded cernible green light and column F willtransmit no disnegative dye images. Therefore, the resulting colorcernible red lighL the other hand Column G will translation will beexactly the reverse of what obtained transmit blue light. However, sincecolumn G is a low h imi f a ti Th t i ol m H QfTacontrast scale. theblue light will be of less intensity bles 1, ll, and 111 will be turnedbottom to top and top then if column G represented a high c n ra im g tobottom. Thus it is possible to obtain two different re- Thus, for thebottom line where only blue light is transsults f h fil or paper; ne tan l tion u ing a mitted, the resulting translation be blue. lllbenegative as the ource image and a econd using a positwee" red andblue, y g hues be Pmduced a5 tive as the source. If the film ismanufactured in three Sh n in Column resultant c010T 05 Colum" H typesaccording to Tables 1, ll, and 111, then it is possible to produce sixdifferent color translations, one of which will be appropriate for theblack and whitescene depicted.

While the present invention has been disclosed as a print film forexisting photographic material, it is to be noted that the element inFIG. 1 may also be utilized as camera film for original photography. Forexample in the field of animated movies, if the artwork is shadedaccording to the graduated steps of a gray scale, then black and whitedrawings can be translated into color. Additionally, the element may beutilized in the field of medical thermography using the standard Barnescamera. The heat patterns of the human body can then be translated intocolor thermographs.

7 fl Gi' i'ififlirates a inb dfiedmbodlmfit of the pies ent inventionwhich may be utilized in the field of medical radiography to produce acolored X-ray film. Thus the element of FIG. 2, which is designatedgenerally by the reference numeral 110, is similar to the element 10 andsimilar numbers indicate identical features. However, the safety filmsupport 12 of FIG. 2 is interposed between the layers and 22.Additionally, the antihalation backing is dispensed with. Also, theemulsion layers 16, 20, 24, and 28 are fabricated to have maximumsensitivity to the fluorescence of calcium tungstate rather than toX-rays per se. The element 110 is placed between calcium tungstateintensifying screens which fluoresce under the action of X-rays, thefilm being exposed on both sides.

While preferred embodiments of the invention have been shown anddescribed herein, it will become obvious that numerous omissions,changes, and additions may be made in such embodiments without departingfrom the spirit and scope of the present invention. For example, a cyanfilter may be substituted for the yellow filter in which case the secondexposure would be made with red light. Similarly, a magenta filter maybe substituted for the yellow filter in which case the second exposurewould be made with green light. As a further example, the exact order ofthe low and high contrast layers may be interchanged. Thus, instead ofthe first and fourth layers being low contrast and the second and thirdlayers being high contrast, the contrasts may be reversed.Alternatively, the first and third layers may be low contrast and thesecond and fourth layers may be high contrast, or the contrasts in thelayers of this latter example may be reversed, etc.

tive-positive masking images (both of which are the same color) may bechanged. These composite masking images need not be confined to thesecond and third layers but may comprise the first and fourth layers.Alternatively, the composite masking images may comprise the first andthird or the second and fourth layers, etc.

Additionally, the four emulsions need not be panchromatic but may besensitized to different colors of the visible spectrum. Thus, the firstemulsion may be made sensitive to red and blue, the second to green andblue, the third to blue, and the fourth also to blue. The film may thenbe printed by white light, and given a second exposure in blue lightresulting in reversal of the two blue sensitive emulsions.

Moreover, the emulsion layers may be made sensitive to a differentportion of the spectrum rather than visible light. For instance, allfour emulsions may be made sensitive to infra-red, ultraviolet, orX-rays.

Alternatively, the top two emulsions may be subjected to solarizationrather than being reversal processed. That is, during manufacture thefilm may be flashed to blue light of sufficient intensity to produce themaximum developable density in the top two emulsions. The film may thenbe exposed to a negative source image by white light, followed by colordevelopment. Thus two negative dye images (solarized) and two positivedye images (unsolarized) may be produced on the same support withoutrecourse to a second development.

While the present invention has been describd and illustrated as a filmor paper comprising silver halide, it is to be emphasized that theinvention is also applicable to non-silver photographic systems. Thus,utilizing the methods and principles discussed herein colored images maybe produced using thermoplastic materials or electrostatic reproducingmeans, for example.

What is claimed is:

1. A photosensitive element for producing a colored image from amonochromatic source image comprising at least four light-sensitivesilver halide emulsion layers, one of said layers having a color couplerfor producing a low contrast positive image of said source image in afirst color out of the colors cyan, magenta and yellow; another two ofsaid layers having the same color couplers in each layer for producing ahigh contrast positive image and a high contrast negative image of saidsource image in a second color of said colors cyan, magenta and yellow;the other of said layers having a color coupler for producing a lowcontrast negative image of said source image in a third color of saidcolors cyan, magenta and yellow.

2. A photosensitive element as in claim 1, and a film supporting layerfor supporting said four silver halide emulsion layers. l

3. A photosensitive element as in claim 1, in which said one and othersilver halide emulsion layers are fabricated of low contrast materialwith a long exposure range and a disposition toward underexposure andunderdevelopment, and said two silver halide emulsion layers arefabricated of high contrast material with a short exposure range and adisposition toward overexposure and overdevelopment.

4. A photosensitive element as in claim 2, in which the bottommost twosilver halide emulsion layers are separated by a gelatine layer and theuppermost two silver halide emulsion layers are separated by a gelatinelayer.

5. A photosensitive element as in claim 1, in which said four silverhalide emulsion layers are panchromatic.

6. A photosensitive element as in claim 1, in which said four silverhalide emulsion layers are sensitive to the same spectral region otherthan visible light.

7. A photosensitive element as in claim 1, in which the bottommost twosilver halide emulsion layers are thicker than the uppermost two silverhalide emulsion layers.

8. A photosensitive element as in claim 2, in which said element furthercomprises an anti-halation layer.

9. A photosensitive element for producing a colored image from amonochromatic source image and the like comprising at least a firstlayer silver halide emulsion having a color coupler for producing anegative image of said source image in a first color out of the colorscyan, magenta and yellow; second and third layer silver halide emulsionshaving the same color coupler for producing a negative image and apositive image both of said source image in a second color of saidcolors cyan, magenta and yellow; and a fourth layer silver halideemulsion having a color coupler for producing a positive image of saidsource image in a third color of said colors cyan, magenta and yellow;said second and third layers producing images having a contrastdifferent from the images produced in the other two of said layers.

10. A photosensitive element as in claim 9, and a color filter betweensaid second and third layers for preventing the passage of light of apreselected color therethrough.

11. A photosensitive element as in claim 10, and a film support betweensaid filter and said second layer.

12. A photosensitive element as in claim 9, in which said first andsecond layers are thicker than said third and fourth layers.

13. A photosensitive element as in claim 9, in which said first andfourth layer emulsions include means for producing extremely lowcontrast images, and said second and third layer emulsions include meansfor producing extremely high contrast images.

14. A photosensitive element as in claim 13, in which said first layeris mounted on an antihalation layer comprising colloidal silver.

15. A photosensitive element as in claim 7, in which said uppermost twosilver halide emulsion layers are separated from said bottommost twosilver halide emulsion layers by a filter layer comprising colloidalsilver,

16. The method of producing a colored image from a monochromatic sourceimage which comprises exposing to said source image a photosensitiveelement having four light-sensitive layers of silver halide and colorcouplers in each of said layers thereon and which is capable ofproducing in different layers a low contrast positive image in a firstcolor of the colors cyan, magenta and yellow, a high contrast positiveimage and a high contrast negative image both in the same second colorof the colors cyan, magenta and yellow, and a low contrast negativeimage in a third color of the colors cyan, magenta and yellow;developing the photosensitive element in an ordinary non-staining firstdeveloper, a second exposure of only the top two layers, developing thephotosensitive element in a second developer which produces four dyeimages in said first, second and third colors associated with silverimages; and removing the silver images and any remaining silver halide.

17. The method of claim 16, in which said silver images and silverhalide are removed by treating said element with a bleaching solution,and thereafter subjecting said element to a fixing bath.

18. The method of claim 16, wherein the element is subjected to aneutralizing solution after treating said element with the firstdeveloper, and the second developer.

19. The method of claim 16, in which the second exposure of said film orpaper element is made from the top with a light source having a colorwhich is absorbed by a color filter situated between the second andthird layers of said element.

20. A photosensitive element as in claim 1, in which said four silverhalide emulsion layers comprise emulsions selectively sensitive to redand blue, green and blue, blue, and blue.

2. A photosensitive element as in claim 1, and a film supporting layerfor supporting said four silver halide emulsion layers.
 3. Aphotosensitive element as in claim 1, in which said one and other silverhalide emulsion layers are fabricated of low contrast material with along exposure range and a disposition toward underexposure andUnderdevelopment, and said two silver halide emulsion layers arefabricated of high contrast material with a short exposure range and adisposition toward overexposure and overdevelopment.
 4. A photosensitiveelement as in claim 2, in which the bottommost two silver halideemulsion layers are separated by a gelatine layer and the uppermost twosilver halide emulsion layers are separated by a gelatine layer.
 5. Aphotosensitive element as in claim 1, in which said four silver halideemulsion layers are panchromatic.
 6. A photosensitive element as inclaim 1, in which said four silver halide emulsion layers are sensitiveto the same spectral region other than visible light.
 7. Aphotosensitive element as in claim 1, in which the bottommost two silverhalide emulsion layers are thicker than the uppermost two silver halideemulsion layers.
 8. A photosensitive element as in claim 2, in whichsaid element further comprises an anti-halation layer.
 9. Aphotosensitive element for producing a colored image from amonochromatic source image and the like comprising at least a firstlayer silver halide emulsion having a color coupler for producing anegative image of said source image in a first color out of the colorscyan, magenta and yellow; second and third layer silver halide emulsionshaving the same color coupler for producing a negative image and apositive image both of said source image in a second color of saidcolors cyan, magenta and yellow; and a fourth layer silver halideemulsion having a color coupler for producing a positive image of saidsource image in a third color of said colors cyan, magenta and yellow;said second and third layers producing images having a contrastdifferent from the images produced in the other two of said layers. 10.A photosensitive element as in claim 9, and a color filter between saidsecond and third layers for preventing the passage of light of apreselected color therethrough.
 11. A photosensitive element as in claim10, and a film support between said filter and said second layer.
 12. Aphotosensitive element as in claim 9, in which said first and secondlayers are thicker than said third and fourth layers.
 13. Aphotosensitive element as in claim 9, in which said first and fourthlayer emulsions include means for producing extremely low contrastimages, and said second and third layer emulsions include means forproducing extremely high contrast images.
 14. A photosensitive elementas in claim 13, in which said first layer is mounted on an antihalationlayer comprising colloidal silver.
 15. A photosensitive element as inclaim 7, in which said uppermost two silver halide emulsion layers areseparated from said bottommost two silver halide emulsion layers by afilter layer comprising colloidal silver.
 16. The method of producing acolored image from a monochromatic source image which comprises exposingto said source image a photosensitive element having fourlight-sensitive layers of silver halide and color couplers in each ofsaid layers thereon and which is capable of producing in differentlayers a low contrast positive image in a first color of the colorscyan, magenta and yellow, a high contrast positive image and a highcontrast negative image both in the same second color of the colorscyan, magenta and yellow, and a low contrast negative image in a thirdcolor of the colors cyan, magenta and yellow; developing thephotosensitive element in an ordinary non-staining first developer, asecond exposure of only the top two layers, developing thephotosensitive element in a second developer which produces four dyeimages in said first, second and third colors associated with silverimages; and removing the silver images and any remaining silver halide.17. The method of claim 16, in which said silver images and silverhalide are removed by treating said element with a bleaching solution,and thereafter subjecting said element to a fixing bath.
 18. The methodof claim 16, wherein the Element is subjected to a neutralizing solutionafter treating said element with the first developer, and the seconddeveloper.
 19. The method of claim 16, in which the second exposure ofsaid film or paper element is made from the top with a light sourcehaving a color which is absorbed by a color filter situated between thesecond and third layers of said element.
 20. A photosensitive element asin claim 1, in which said four silver halide emulsion layers compriseemulsions selectively sensitive to red and blue, green and blue, blue,and blue.